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' UNITED STATES PATENT OFFICE;

ALBERTO ROVELLO, OF TURIN, ITALY.

PRODUCTION OF COPPER BY ELECTROLYSIS.

SPECIFICATION forming part of Letters Patent No. 405,604, dated June 18,1889. Application filed April 2, 1889. Serial No. 305,681. (No model.)Patented in Italy September 30, 1885, XXXVII, 259, and March 31,1887,XLI, 386; in France January 27, 1886,No.173,753,

and September 16, 1887, No. 186,878; in Belgium October 5,

1886, No. 74,738, and September 30,1887,N0. 78,910 in Spain December20,1887,No. 11,888 inEngland August 24,1888, No. 12,208, andinAustria-Hungary September 15, 1888, No. 15,137.

T0 at whom it may concern:

Be it known that I, ALBERTO RovELLo, a subject of the King of Italy,residing at Turin, Italy, have invented certain new and usefulImprovements in Apparatus for the Production of Oopperby Electrolysis;and I do hereby declare the following to be mfull, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same, reference being hadto the accompanying drawings, and to letters or figures of referencemarked thereon, which form a partof this specification; and be itfurther known that I have obtained patents in the following countries:Italy, September 30, 1885, Vol. 37, No. 259, and March 31, 1887, Vol.41, No. 386; France, January 27, 1886, No. 173,753, and September 16,1887, No. 185,873; Belgium, October 5, 1886, No. 74,738, and September30, 1887, No. 78,910; Spain, December 20, 1887, No. 11,838;Austria-Hungary, September 15,1888, No. 15,137; England, August 24,1888, No. 12,208.

The invention relates to the extraction of copper from the cupreous lyesobtained either in the treatment of copper ores by what is called thewet process or in the lixiviation of the ashes obtained in the burningor roasting of cupreous pyrites in the manufacture of sulphuric acid. 7

The object of my invention isto recover the copper'from such lyes byelectrolysis; and it consists, essentially, in the construction of theapparatus employed, substantially as hereinafter fully described, andset forth in the claims.

The recovery of the copper from the lyes referred to has heretofore beeneffected by treatment with scrap-iron or cast-iron to precipitate thecopper in an impure form called cement-copper, containing at mostseventyfive per cent. of copper. This cement-copper has to undergovarious treatments-such as compression, desiccation, smelting, andrefining-in order to obtainacommercialproduct. In this process theproportion of iron should theoretically be in proportion to thecopperthat is to say, in the ratio of the chemical equivalents or lessthan one of iron to one of copper precipitatedyetin practicetheproportion of iron is usually double or nearly double that quantity.

By my improved process pure copper is obtained directly from thesolution or lye, thus dispensing with the expensive processes referredto, the proportion of iron used being but slightly greater than thetheoretical proportion, while no external electric current is required.

In carrying out my invention I employ an apparatus in which, theelectro-negative or cathode consists of wrought-iron, though castironmay be used instead, or zinc, the electropositive or anode consisting ofcourse of copper, and when the two are included inashort circuit theresistance is so slight that practically the whole of the electricalenergy is utilized in the electrolytical treatment of the lyes. Theelectro-motive force of the elements, con sisting of copper and ironwith an interposed porous diaphragm and two liquidsnamely, a cupreoussolution and a ferrous solution is at least 0.60 volt; but if zinc issubstituted for the iron the electro-motive force increases to one volt.If, therefore, the apparatus has an internal resistance of, say, 0.003ohm, the

E current g1 ven by the formula R will amount to two hundred ampereswith an iron cathode and. three hundred and thirty ampres with a zinccathode. Consequently at the rate of 1.19 gram of copper deposited perampere and per hour such an apparatus will yield every twenty-four hoursa product in the first case of more than five kilograms of copper and ofmore than nine kilograms in the second case. In order to reducetheinternal resistance to a minimumsay less than 0.003 ohm-it isnecessary to employ large electrode-surfaces as well as diaphragms ofvery small specific resistance, and to arrive at these desired results Ihave devised the apparatus which I will now describe, reference beinghad to the annexed drawings, in which Figure 1 is an end elevation. Fig.2 side elevation.

isa

Fig. 3 is a partial top plan View. Fig. 4 is an elevation of one of thecell-frames, and Fig. 5 is atransverse vertical section of a few of thecells.

The apparatus consists of a series of cells of even number, formed in aninclosing-case by diaphragms k, of a porous material, preferablyartificial parchment or parchment-paper, though parchmentdiaphragms maybe employed.

With a view to economy in construction and to facilitate the dismantlingof the apparatus when this becomes necessary from any cause, I havedevised the following construction:

The inclosing-frame consists simply of two heads or ends H H, which,like all the wooden parts of the apparatus, are preferably made of pine.These heads are formed of crossboards joined together fluid-tightas, forinstance, by a feather-joint, as shown-and between which heads theframes I I are clamped or tied by means of tie-rods b that extendthrough the heads and through vertical bracebars a.

At one end of the apparatus the head H has four ports, to which areconnected overflow-pipes h h and exhaust-pipes g g, said pipes beingpreferably of a flexible material, the pipes g g being simply providedwith a clamp g for compressing and closing the same, though they may beprovided with other suitable means of closure-such as a valve orstop-cock. I prefer the clamps, as a metallic contact with the lyes isthereby avoided, said clamps acting from the outside of the pipes, andform a very simple and effective means of closure. In the opposite headH of the apparatus are formed two ports, to which are connected twofeed-pipes ff, surmounted by funnels f f respectively.

The intermediate frames I that serve to form the cells are constructedof a lower cross-bar 2', vertical bars '5, at the upper end of which isformed a rabbet on opposite sides for the reception of the lighter crossbars or strips Z, each vertical bar having two such strips, as shown inFig. 5, to which the upper edge of the diaphragms 7c are secured orbetween which such diaphragms are clamped.

In the lower cross-bars i of all the frames I I are formed two ports mand m, located near the opposite ends of said bar inside the vertical orside bars I, in each of which is also formed a port m and mrespectively.

The ports on m in one set of frames I communicate with vertical andhorizontal passages n and n, respectively, and the ports m m in theother set of frames I communicate, respectively, with like vertical andhorizonal passages n n, as shown in Figs. 4 and 5, the diaphragmssecured to or clamped between the frames being provided with holesregistering with the ports m and m and m m, respectively.

The frames may be further strengthened by intermediate vertical stays rs, as shown in dotted lines in Fig. 4, through which the tie-rods pass,a fluid-tight joint being formed in any desirable manner by suitablepacking. The number of these vertical intermediate braces willnecessarily depend upon the dimensions or capacity of the apparatus, andsuch braces are dispensed with when the apparatus is of small capacity,as will be readily understood. It will be seen that when these frames Iand I are assembled in alternate order there will be formed fourcontinuous passages m m m mfi, and that the said passages will be incommunication with the inner spaces or cells through the passages n n nn. The feed-pipes f and f and the exhaustpipes g and g are connected tothe opposite ends of the passages m and m, respectively, while thepassages m and m are connected with the two overflow-pipes h and h,respect ively. The exhaust-pipes g and g being closed, a liquid fedthrough pipe f will pass into passage m, and thence through passages ninto every alternate cell formed by the diaphragms k, which, when full,will overflow through the horizontal passages '11, into passage m, andthence to and through overflowpipe 71. A liquid fed through pipe f willpass into passage m, thence through passages n into every alternatecell, the overflow from said cells passing out of the apparatus throughpassages 01 m to and through overflowpipe h. I

The diaphragm is may be secured to the frames in any usual or preferredmanner, or

they may simply be clamped between the.

apparatus very materially.

On the top of the apparatus are laid cross beams or bars 0, to which aresecured the wooden supports 0 and 0 for the electrodes E and E,respectively, said supports being made conductive through the medium ofa strip of sheet-copper, (indicated by 6 one end of which strip projectsbeyond the support and is connected by a suitable clamp to a conductor.These supports 0 and 0 are also arranged alternately, the ends 6 of thestrips 6 of sheet-copper for the supports 0 being connected to aconductor 0 at one end of the apparatus, while the ends a of the strips6 for the supports 0 are connected to a conductor C at the opposite endof the apparatus.

The negative or copper electrodes E are supported from the supports 0 bymeans of copper hooks d, and are connected through the ends 6 of thecopper strips 6 with the conductor 0,- and the positive or iron or zincelectrodes E are suspended from like hooks d from the supports 0, theends e of whose copper strips 6 are connected with the conductor C.

in those cells which are in communication IIC with the feed-pipe f, andthe positive electrodes E in those cells which are in communication withthe feed-pipe f.

Instead of connecting the ends 6 and e of the cond ucting-strips 6according to their polarity with separate conductors, all the strip endse and 6 may be electrically connected at either end of the apparatuswithout regard to their polarity, so that there will be no distinctpoles, while the short external circuit thusestablished will present theleast possible resistance to the passage of the current, thus materiallyincreasing the efficiency of the apparatus.

The cupreous lye is fed through pipe f to the cells in which aresuspended the negative electrodes E, and a weak solution of the salt ofthe same metal of which the positive electrode is formed is fed throughpipe fto. those cells in which the positive electrodes E are suspended.Thus, if the cupreous solution is one of sulphate of copper, the othersolution should be one of a sulphate of iron or Zinc, according as thepositive electrode is of iron or zinc. These solutions are fedsimultaneously and in such manner as to cause them to rise together andslowly in their respective cells, the overflow passing out through theoverflow-pipes h and h, respectively, as hereinbefore described, theelectrolytical process being a continuous one.

The conductors C and 0, connecting the copper strips 6 6', beingshort-circuited, the resistance to the passage of the current is reducedto the minimum, while the electrolytical action takes place at once, andthe elimination of the copper will proceed, so that the cupreoussolution fed to the negative-electrode cells at the bottom thereof willbe de prived of nearly all of its copper as it passes out of the cellsat their upper end through the passage m and overflow h.

The overflow may be collected and again. passed through the sameapparatus; or a number of such apparatus may be arranged and connectedin series, the overflow of cupreous solution being conducted from oneinto the other until deprived of its copper; or such impoverishedcupreous solution may be enriched by using it as a lixiviating agenteither in the treatment of copper ores by the wet process or forlixiviating the ashes resulting from the manufacture of sulphuric acid.I

The apparatus may also be employed in the recovery of zinc fromsolutions of such, the negative electrode being of course of zinc andthe positive of iron, the liquids used being a solution of a sulphate ofzinc which may be obtained in the lixiviation of sulphate ores and aweak solution of sulphuric acid or of a sulphate of iron.

In the production of zinc I preferably con nect the conductors with adynamo-electric machine, and so arrange the connections that eachapparatus or group of such is made to work in series or parallel arcs,and are supplied with a current, giving at the pole-connections adifference of potential not less than 0.34 volt, and not exceeding 1.4.0volt, so as not to decompose the water of the solutions.

Having described my invention, what I claim, and desire to secure byLetters Patent, is

1. The herein-described electrolytical apparatus, consisting of a tankor casing formed of two heads and a series of intermediate framesdetachably connected together, said frames being provided with porousdiaphragms dividing the tank into an equal number of cells, a feed andexhaust duct for each alternate series of cells having its inlet anddischarge, respectively, near the bottom of the tank at opposite endsthereof, and an overflow for each of said alternate series of cells, incombination with electrodes for the cells and an electrical circuitincluding said electrodes.

2. The herein-described electrolytical apparatus, consisting of a tankor casing composed of two heads, whereof one is provided with twofeed-ports and the other with two exhaust and two overflow ports,arranged as set forth, a series of intermediate frames, each providedwith diaphragms that divide the tank into a plurality of cells, each ofsaid frames having four ports m m m m, whereof ports on" and m registerwith said overflow-ports and communicate by ports a" n with the interiorof the cells, the two other ports m m in the bottom of said framesregistering with the feed and exhaust ports in the heads andcommunicating by ports n n with the interior of said cells, said partsbeing detachably connected together, for the purpose set forth.

3. The herein-described electrolytical apparatus, consisting of a casingor tank composed of two heads whereof one is provided with two feedportsand the other with two exhaust and two overflow ports, arranged asdescribed, a series of intermediate frames provided with porousdiaphragms that divide the tank into a plurality of cells, a feed andexhaust duct for each alternate series of cells, in communicationtherewith and with the corresponding ports in the heads of the tank,-

